Apparatus for pasteurizing and deodorizing liquids



" Sept. 20, 1938.

H. c. HoRNr-:MAN 2,130,645

APPARATUS FOR PASTEURIZING AND DEODORIZING LIQUIDS Original Filed July21, 1933 4 Sheets-Sheet l SePt- 20, 1938- H. c. HORNEMAN 2,130,645

APPARATUS FOR PASTEURIZING AND DEODORIZING LIQUIDS original Filed July21, 1953 4 sheets-sheet 2 Sept. 20, 1938. H. c. HORNEMAN 2,130,645

APPARATUS FOR PASTEURIZING AND DEODRIZING LIQUIDS Original Filed July21, 1953 4 Sheets-SheetI 3 aww/who@ m a M C n W H Sept. 20, 1938. H, c.HORNEMAN APPARATUS FOR PASTEURIZING AND DEODORIZING LIQUIDS OriginalFiled July 2l, 1953 4 Sheets-Sheet 4 Patented Sept, 20,v A.,

UNITED STATES PAT-ENT? "for-"Fics y poration of Maryland Renewed Marchl1, 1938 Application July 21, 1933,- Scrial No. 681,656

z calm. (ci. eis- 251) This invention relates to an apparatus forpasteurizing, deodorizing and cooling liquids. and also includes a'method of pasteurizing, deodorizing and cooling milk products such asmilk or 5 cream used directly or in the manufacture of butter, cheese,ice cream and other dairy prodp ucts.

The primary object of this invention is to provide an apparatus wherebymilk or cream with l an imparted ilavor or flavors, due to fermentationand/or feeds can be restored to its natural flavor. While conventionalmethods of 'pasteurizing and cooling milk or cream do, to some extent,tend to improve the iiavor of these products l by partially volatilizingthe off-davor imparting substances from said products, the presentinvention augments and magnifles this volatilizing effect. to such anextent as to reduce the oiliiavors to a negligible quantity in the end-20 product.

In carrying out the present invention, very complete subdivision ofcream or other lactic uid is obtained with consequent maximumdeodorization. This result is secured by first compress- 25 ing thelactic-fluid with steam or other inert gas while pasteurizing and mixingthe fluid with the i gas, and producing, initially, a division of thecream particles. This treatmentof the cream is continued by introducingthe A compressed stcam-water-cream mixture through a reduced outlet intoa condition of reduced pressure, i. e. a vacuum chamber, whence a secondextremely line subdivision of the particles'takes place. This is due tothe release of the mixture from a state of compression to a condition ofexpansion.

This release results in instantaneousbreaking up of the particles to adegree of subdivision heretofore unattained and takes place with violentand explosive force.

40 Briefly stated, subdivision of the particles is iirst carried outunder a condition of compression immediately followed as a continuousstep by greatly enhanced subdivision, made possible by ihe instantaneousrelease of the preliminarily 45 divided particles from a state ofcompression to a condition of violent and, in fact, explosive expansion.

The vacuum chamber is characterized by being heated. In this manner,condensation of water 50 vapors and odoriferous volatiles and theirattendant objectional return to the cream is prevented, f

Likewise, separation of liquid and vapor phase cream is obtained.` Infact, the cream-steamwater mixture isv concentrated by removal ofmoisture and odoriferous volatile substances, with the result that theend product has improved organolyptic qualities and a substantiallyslightly reduced moisture content from that of the original cream. 'Ihatis, although dilution will take place in the initial compression andshattering of the cream particles with steam, this water is removedinthe subsequent expansion subdivision treatment, and the ilnal eil'ectis one of concentration of the original cream.

A particular object of this invention is to provide an apparatus wherebymilk or cream or other milk products are improved by eliminating inlarge measure, volatile substances therefrom, thereby rendering themsuitable for manufacture into cheese, butter and ice cream products of.excellent quality.

.A further object is tocombine the operation of pasteurizing,deodorizing and cooling milk or cream in one compact unit, therebyreducing the amount of handling of these products and minimizing theirexposure to metallic surface and other innocuous influences.

Other objects and novel features and advantages ofI this invention willbe apparent from the following specification and accompanying drawingshereinafter more fully described and claimed. The preferred form andarrangement of my improved apparatus, as shown in the accompanyingdrawings, is as follows.

Referring to the drawings:

Figure 1 is an elevation partly in section of one form of apparatus. V

Figure 2 is a detail view of the distributor head. Figure 3 is anelevation partly in section of another form of apparatus. y

Figure 4 is a top view of the apparatus shown in Figure 3.

Figure 5 is a view of a further embodiment of the invention.

Figure 6 is a detailed view of a iioat 'and slide` valve.

Figure 7 is a detailed view of the nozzle shown in Figure 5.

Figure 8 is a detailed View of another type of distributor head,

Figure 9 is an elevation partly in `section of a 50 modiilcation.

Figure 10 is an elevation partly in section of a modification. Figure 11is an elevation partly in section of a modification. 55

Figure 12 is an elevation partly in section of a modiilcation.

Figure 13 is an elevation partly in section and showing a heating meansfor the circulating fluid, and 1 Figure 14 is a fragmentary view of theheating jacket provided with an electrical heatingmeans.

In Figures 1 and 3, 9 represents a closed metal container which isequipped to operate as a vacuum chamber, and has a removable cover forready cleaning oi' the chamber. The liquid to be treated is introducedcontinuously into surge tank III through pipe 9 from a forewarmer, whereit has 'been preliminarily heated to a suitable temperature. From alaterally extending outlet pipe II, as shown in Figures 4 and 6, of thesurge tank I0, the liquid is transferred through the pipe I2 and pipe I3 to the vacuum chamber 9, the reduced pressure in the latter obviatinguse of a pump. A steam line Il has its open or outlet end in the line I2above the outlet II and steam is intro-` duced in suilicient quantity toheat the liquid in the linel I2-I9 to a pasteurizing temperature, whichtemperature is automatically maintained by a thermostatic control Ilactivated from the bulb at I9. 'I'he oream-water-steam mixture from lineI2-I3 is distributed in vacuum chamber 9 `by a distributing head I1,shown in detail in Figures 2 and 8, through the narrow preferablyelongated or continuous, peripheral opening I9..

vapors and gases released by the introduction of the liquid-steam-watermixture into the vacuum chamber 9 through head I'I are carried offthrough the port I9 and pipe 20 to the condenser 2i and vacuum pump 22.T he liquid portions of the cream or milk will coalesce and collect atthe bottom of vacuum chamber 9 and will pass by outlet pipe 23 throughthe cooler system 24 and can be continuously removed and lrecovered bymeans of a suitable pump through pipe 26.

Surrounding the chamber 9 is a spaced wall `21 constituting a jacketwithin which is circulated a heating medium such as gas or liquid,preferably hot water. 'I'he inlet and outlet for the circulating mediumis indicated 9' and 9" respectively.

A preferred form of distributing head I'l is illustrated in detail inFigure 2 and supported on a 'sanitary T-coupling I1'. This distributinghead comprises two members 28-29 adjustablyconnected by bolts to varythe width of the spray outlet. The bolts are provided with wing nutsengaging springs disposed between the wing nut and the adjacent surfaceof the member 29. Interiorly of the member 28 are projections 30',through `which the bolts extend and which projections are of equallength and of a size whereby suitable shims may be interposed betweenthe bottom of the projections and the top surface of the member 29, topermit of an extremely ilne and critical range of adjustment for theoutlet opening I9. In this connection, the outlet opening I8 issubstantially continuous or elongated and, as

shown, is relativelylnarrow. The baille 3| is connected to the head asshown and diverts the finely divided particles downwardly to reducepossibility of entrainment, as will later be described.

Referring to Figure 8. the head I 1 comprises the two members 29, 29,which are centrally connected by a singlebolt 90 and arranged about thebolt are a plurality of spacer members 28 having reduced ends 29 looselydisposed in the members 28 and 29 respectively. When it is desired toadjust the outlet opening between the members 29 and 29, suitable shimsare fitted about the reduced f ends of the spacer members to assure avery fine adjustment of the outlet opening I9.

A suitable float-operated slide valve III', as shown in Figure 6,controls the outlet from the tank III, which will overcome anypossibility of releasing the vacuum in chamber 9 if the liquid reaches apredetermined depressed level, as when the cream supply temporarilystops.

The steam line I4 is projected into the line to have its outlet abovethe outlet from the tank Il. I'flnd this is not only efilcient in myprocess, but also overcomes any tendency for the steam to enter the tankand produce interruption of continuous ilow of cream or milk in the lineI2-I3.

'I'he head I1 is relatively small, as compared to the size of thechamber, as shown. It is preferably substantially centrally located,that is, sutilcientiy below the outlet port or ports I9 to prevententrainment and far enough from the bottom of the chamber to give thefalling particles projected 'from the head a sufficient time foradequate separation out of the vapor and liquid phase constituents andcooling of the latter.

The line I2-I3 is of a length and diameter to enable the lactic fluid tobe continuously supplied from tank I Il to the head I1 and the lacticfluid is simultaneously pasteurized and intimately mixed with the steamto be broken up and subdivided.

The heating jacket 21 assures that the1 inner wall surface of thechamber 9 will be at a constant temperature, and serves to reduce to aminimum the possibility of condensation of water vapors and gases on thewall, as well as produce a prolonged separation of vapor and odoriferousgases from the liquid phase particles.

4'1"he heating jacket 21 serves to maintain the chamber 9 at all timesheated to the temperature of the boiling point of the cream or slightlyhigher, corresponding to the conditions of vacuum in chamber 9.

It will be observed that the cream is treated under a controlledtemperature and under influence of the vacuum from the time it leavesthe surge tank until the separated constituents are collected. That is,the Acream is continuously under the influence of thevacuum i. e. adirectional influence in the line I2-I3, and a direct expansion in thechamber 9, and heated and compressed in the steam line and expanded andheated in the vacuum chamber.

The cooling means 24 operates to lower the temperature of the pumpedcream, so that the latter will be substantiallyfree of foaming whenpumped continuously. f

In Figure 5, I have illustrated an alternative arrangement in which oneor more peripheraily disposed spray nozzles I'i are provided. Thesenozzles I1 are preferably spaced apart and the jet openings areconstructed to project the mixture toward the center of the chamber andslightly downwardly, to facilitate the gravity fall of the liquid phaseof the steam-cream-water mixture. These nozzles are of any suitabledesign, such as commonly used for production of powdered dairy productsby a spray process.` 'I'he nozzles shown have a spirally grooved andloose member in advance of the outlet port and will produce the socalledsolid cone spray.

The disclosure inFigure 3 is substantially similar to Figure 1, exceptthere are a plurality of spaced suction outlets I9, as shown in Figure4, and an ejector-condenser system is utilized instead of a wet pump andcondenser asin Figure 1. l The pressure differential between'the mixtureinthe line |2-I3 and the vacuum chamber 9, and the relatively narrowoutlet opening I8 in the head, causes a spontaneous and violentseparation of the mixture in the vacuum chamber.

That is, the liquid and vapor phases are discharged through the narrowelongated outlet lil and are broken up or particulated intosubstantially a fog from which the cream or milk on thev one hand andthe water-vapor and gases on the other separate out in the chamber 9.

The diameter of the line I Z- and the peripheral dimension of themembers defining the outlet in the head, and the diameter of the steaminlet and the pressure of the steam are selected or controlled, toproduce the required result within (1) the range of adjustment permittedfor the outlet opening in the head, and (2') the range of the reducedpressure maintained in the vacuum chamber and the size thereof. In otherwords, it is essential that these parts beso related that the properpressure differential will be established and that sufficient time willbe permitted before the mixture enters the chamber, (1) for intimatemixing of the steam and lactic fluid, (2) for reaching a temperaturesufficient for pasteurization and (3) for compressing the mixture topreliminarily subdivide the same. In this manner, the mixture dischargedfrom the head will be subjected to violent expansion and separation ofthe volatile and non-volatile constituents, and the liquid phase isfinely sub-divided. Therefore, due to the disposition of the head withrespect to the chamber, as described above, and the heated inner wallsurface of the chamber, the volatile constituents will be separated anddrawn oil Without objectionable condensation on the wall or entrainmentof the non-volatile constituents, which latter will gravitate and becollected in coalesced condition at the bottom'of the chamber.

'I'he invention is applicable to milk, cream, ice cream mix and milkproducts in general, and for convenience, I shall describe the treatmentof sour cream (any cream in which the titratable acidity calculated aslactic acid exceeds .25%) to improve the same and render it satisfactoryfor the manufacture of butter.

Conventional practice comprises reduction of the acidity of the sourcream to a point at which satisfactory churning may be accomplished.Normally this point lies within a range from .18 to .25%, as lacticacid. Upon completion of the acid reduction, the practice is topasteurize in any suitable manner. The neutralizing and pasteurizingsteps exert some flavor improving effects, due to the volatization ofcertain flavors.

Referring to Figures 9, 10 and 11, I have illustrated a modification ofthe heating jacket 21. In these figures, the chamber 9 is heated by acoil 2l placed therein through which the heating medium, i. e. steam orhot water circulates to maintain the temperature at or preferablyslightly above the boiling point of the cream under the correspondingconditions of vacuum.

In Figure 9 the coil 21' is disposed below the distributor head, inFigure 10 surrounding the same, and in Figure 11 above the head. All4three dispositions of coils may be used in some cases and combined inany suitable manner.

In Figure 12 I have illustrated the coil 21 of Figures 9, 10 and 1l aselectrically heated by a conventional electrical heating element 28' andin Figure 14, I have illustrated a fragmentary view of the jacket 21heated by a similar electrical heating element.

In Figure 13 I have illustrated a means of supplying a heatedcirculating medium such as hot water to the jacket 21 or coil 2l'. 'Ihewarm water from the condenser 2| is pumped through line 35 in anysuitable manner and a steam ejector 36 is employed to raise thetemperature of the water as desired. The ejector 36 is controlled by asuitable thermostat 3l to regulate this heating of the Water and assurethat it will be delivered to the jacket or coil at a constant requiredtemperature.

By the processes now to bebdescribed, I find that more effectiveimprovement of the cream is attained. I shall assume, as in ordinarycases, that the sour cream is collected in a suitable vat with means formixing and sampling and possesses varied percentages of acidity.

Process A The cream, as received, is warmed to a point where it can beconveniently handled with the usual dairy equipment. Normally, thistemperature will not exceed F., preferably SiO-100 F.' Thereafter, theacidity is reduced, if necessary, by a neutralizing treatment asunderstood in the practice. vI find it preferable to operate with theacidity of the sour cream at approximately .3% calculated as lacticacid.

After a suitable time has been allowed for the action of theneutralizing agents, the cream is then quickly heated to a temperatureof 15G-165 F., and preferably not to exceed F. in a conventional heater,such as one of the continuous type.

The cream at this temperature is transferred to the tank I0 through pipe8. When proper level in the tank il) is attained, the float will openthe valve and by virtue of the difference in pressure between theoutside atmosphere and the chamber 9, in which a reduced pressure isbeing maintained, the liquid will be forced into the line I2-I3 andthrough the distributor head i1 into the vacuum chamber.

As soon as flow is established, steam under a pressure of substantially50 to 100 lbs. is introduced into the cream in the line l2 through thesteam line I4, as shown in Figures 1 and 3. The outlet of the steam pipeextends above the lateral outlet il of the tank I0. This assures thatthe steam will travel in a direction toward the Vacuum tank whereby (1)the pressure of the mixture in the line |2--i3 is increased, (2)intimate mixing of the steam and cream is accomplished, since noopportunity is presented for building a back pressure or forcing steaminto the tank I0, and (3) the steam is introduced at a safe point andrelatively close to the outlet of the tank, so that a maximum contact ofliquid and steam is maintained from the tank to the vacuum chamber andhead.

In this steam treatment the latent heat of the steam is very largelytransferred to the cream (1) part of the cooled steam condenses and (a)the heat of condensation also is transferred to the cream, resulting ina cream-water mixture having a pasteurizing temperature of substantiallyF., (b) the condensation of the steam with sudden collapse of the steambubbles upon coming in contact with relatively cooler cream will cause abreaking up of the fat globules with consequent release of volatileodoriferous substances occluded within the fat clumps, and (c) theheating eilect, the release of 4volatiles and the uncondensed portion ofthe steam produces a compression, i. e., a building up o pressure in theline I2-l3, and (2) the uncondensed steam exerts a sweeping action inthat it serves as' a carrier for the volatile or vapor phase constitu-,ents of the cream Vreleased by the shattering actions and heatingeilect of the steam.

This heating or pasteurizationv of the cre and its ii'iterinixing'vwith, the steam, as wellas the breakingup ofthe fiat clumps withreleaseof volatiles, takes place 'during the continuous passage of themixture -from the tank and steam outlet tofthe distributor. head I1 andunder the influence of the vacuum.

In connection with the use of steam, it will be understood that otherinert gases may be` em'- ployed. Steam is most convenientand economicaland it will be used in such quantities and pressures as to raise thetemperature of the mixture to the pasteurizing temperature ofsubstantially 185 F. The temperature of thecream in the line can becontrolled) by regulating the amount of steam or cream or both suppliedto the line and"(2) by regulating, initially the temperature of thecream. 1

Referring to Figure 2, the outlet I8 of the distributor head I1is'ad'justed, so that the total area of the peripheral opening is asmall fraction, for example one-tenth (115) of the crosssectional areaof the line I 2-I3.

This fraction will be determined by the condition of the cream, i. e.,the amount of deodorization required. In the case of feed avors such asonion and v`garlic, which are relatively easily volatilized, the openingof the distributor head can be set at amaximum. Again Where theoffflavors are of a more tenacious character and of fermentation orbacteriological origin, the opening is reduced to a minimum. It will beobserved that the steam line I 2-l3 extends into the vacuum chamber andcommunicates therewith through the head l1 which is substantiallycentrally disposed in the chamber.

n the outside of the head, there is maintained a condition of reducedpressure preferably 2425" and up to 28" or more of vacuum. On the insideof the head is present a cream-watersteam mixture under suilicientpressure as above described to produce a pressure differential ofsubstantially one atmosphere. This will vary with the conditions ofoperation as outlined above, and the diil'erential may be in someinstances greater or less than one atmosphere.

By reason of the small area of the outlet opening IB in the head and thepressure differential maintained as just described, the cream-watersteammixture is ejected into the chamber with violent and spontaneousexpansion. A fog of finely divided cream and water vapors and gases isproduced. 'I'he ilnely divided cream particles of the fog graduallycoalesce and drop to the bottom` of the chamber where they are collectedand` continuously removed while the vapors and gases are withdrawnthrough the outlet I9 by the vacuum pump to the condenser system.

The relative iineness or division of the cream particles and consequenteffective deodorization and rapidityiof cooling, is greatly enhanced bythe use of a distributing head having a substantially continuouselongated or peripheral and narrow opening. The sudden release of thecream at a pasteurizing temperature into the vacuum chamber withinstantaneous cooling to the bolling point of the liquid is instrumentalin preventing at thev prevailing pressure, which point normallyapproximates 13D-145 F., formation of grainy texture or a weak body inany resulting butter or manufactured milk product. For example, thelength of the peripheral opening in Figure 2 will be substantiallynineteen (19) inches and the width of the opening will be substantially0.025 inch and the diameter of the line I2-I3 substantially two andone-half (2l/0 inches or in equivalent ratios.

By reason of the use of a distributor head and the spontaneous andviolent ejection of the water-cream-steam mixture due to the pressurediiferential, I greatly reduce foaming and consequent cream lossesthrough entrainment;

'I'he inclined walls of the opening I8 and baille 3| act` to deflect thefog downwardly, so as to diminish the possibility of entrainment of thecream particles with the vapors and gases withdrawn through the outleti9. The area of the baille is such that it will effectively deect themajor portion of the fog without, however, restricting the net free areabetween the outside periphery of the baille and the internal wallsurface of the chamber to such a point that the average velocity of thevapors does not attain a critical velocity of entrainment, e. g., twenty(20) feet per second for Water vapor.

The chamber 9 is heated by means of the heating jacket 21 and thetemperature thereof and of the inner exposed Wall of the chamber ismaintained substantially constant and at the temperature correspondingto the boiling point of the cream under the conditions of vacuum beingmaintained and preferably slightly higher, e. g., with a vacuum of24-25", the water circulating in the jacket is maintained atsubstantially 145-130 F. I nd that by using a heated chamber under theconditions of temperature and vacuum set forth above, that thedeodorizing eiect is increased, because of the fact that I cancompletely prevent any condensation of vapors or gases on thewall of thechamber and consequent return of separated odoriferous substances to thecollected cream in the bottom of the chamber. By maintaining thisincreased temperature on the wall, I also prolong the evolution of steamor evaporation from, as well as consequent deodorization of, the creamparticles as they coalesce and gravitate.

It will, therefore, be seen that the initially warmed cream isintimately mixed with steam and subjected in the line I 2-I 3 lunder theinuence of the vacuum in its passage to the evacuated chamber, to apasteurizing .treatment and concomitantly there takes place a breakingup of the fat clumps with resultant release of odoriferous volatilematter. 'I'he steam and vapors act as a carrier for such evolved gases.The resultant mixture is compressed and a pressure differential is setup between the reduced pressure maintained in the evacuated chamber andthe cream-steam-water mixture in the line.

By reason of the narrow and elongated opening in the head and thepressure differential, the mixture is discharged with spontaneous andviolent expansion into the heated vacuum chamber in a very finelydivided condition. The head is positioned centrally with respect to thechamber,

whereby there is sutlicient time for the separation of the liquid andvapor phases, so that (1) the cream will coalesce and gravitate withoutentraining vapors or odorlferous gases, and (2) the vapors and gases donot entrain the cream and also they are prevented from condensing heatedchamber.

A The `substantially spontaneous and violent release of the mixture withcreation of a fog produces (l) cooling of the liquid phase as wellunderstood because of withdrawal of heat by evaporation in the vacuumchamber, and (2) the water vapor and gases carrying odoriferoussubstances previously released in the line l2-l3\continue to have thisfunction in the chamber .and are the vehicle by which the odoriferoussubstances are carried from the chamber to the condenser system. In thismanner, deodorization is accomplished effectively and an improved creamis collected at the bottom of the chamber. vRecontamination is preventedsince the chamber is heated, and thus condensation on the wall isprevented, as well as prolonged evaporation of water and evolution ofgases from the cream particles assured.

The cream at substantially 13D-145 F. is withdrawn from the bottomoutlet 23 of the chamber and passed through the system of coolers 2l bymeans of a pump 25 and discharged through pipe 26. The speed or capacityof the pump 25 will be adjusted automatically or manually to remove thecooled cream at substantially the same rate as the liquid collects atthe bottom of the chamber. Under these conditions of inow and outflow,no appreciable dilution of the treated cream will ensue inasmuch as theamount of dilution introduced by the condensation of the injected steamin line I2-I3 is evaporated and withdrawn in the vacuum chamber asdescribed. That is, the cream-steam-water mixture is condensed orconcentrated in the chamber 9 to remove both the volatile odoriferousvapors and condensed steam.

The cream collected from pipe 26 is recovered in pasteurized condition,greatly improved as regards flavor and odor, and is of excellent qualityfor manufacture of dairy products. The treatment described does notimpart any detrimental properties to the cream, which in any way affectsits suitability for butter making, as evidenced by the fact that thereare no increased butterfat losses in the butter milk or any undesirablebody characteristics imparted to the resulting butter.

Process B This process is distinguished from Process A in that there isno initial reduction of acidity in the case of sour cream. That is, inthis process the pasteurized deodorized cream is neutralized, ifnecessary, after discharge from the outlet 23 or the discharge pipe 26.In the event that the cream under treatment has an initial andappreciable acidity, its pasteurization and deodorization isaccomplished without recourse to an initial neutralization or acidreduction and without detrimental curd formations, due to the breakingup of the cream in the line |2-I3 and the chamber 9 as described.

I have found that it is possible to pasteurize the sour cream, and bythis process, in some cases, a better pasteurization is obtained.

It will be observed that with the present invention, the cream isejected into the vacuum chamber with violent and spontaneous expansionwhereby the` liquid and vapor phases are eectively separated. The vacuumchamber thereby the fore constitutes a separating chamber in which theoptimum amount of deodorized cream is recovered.

Further, it will be observed that with the present invention the creamis continuously pasteurlized and partially deodorized in advance of thedistributor head, and in this condition is ejected as described toassure a very thorough separation in the vacuum chamber. In other words,there takes place in the line I2-I3 not only afpasteurization and abuilding up of pressure, but as well, an initial or partial separationof the liquid and vapor phases of the cream.

VAs heretofore described the cream is heated (1) in the steam line |2-I3and (2) in the vacuum chamber, and in each case while under theinfluence of the vacuum. That is, the compressed mixture in the lineI2I3 is under the directional influence of the vacuum in cooperationwith pressure and velocity of the mixture in the line. Of course, in thevacuum chamber the uid is under the direct expansive influence. This isaccomplished continuously without hardening of the curd or curdconstituents and the heating of the chamber 9 assures maximum constantseparation and removal of volatiles including condensed steam.

'I'his application is a continuation in part of my co-pendingapplication Serial No. 654,069, filed January 28, 1933, which hasmatured into Patent No. 2.022.419, dated November 26, 1935.

I claim:

l. An apparatus for treating liquids such as lactic fluids comprising avacuum chamber, means for maintaining reduced pressure therein includinga withdrawal passage adjacent one end of the chamber, a linecommunicating with a source of liquid supply and extending within saidchamber, said line terminating at its end Within the chamber in areduced outlet whose total cross-sectional area is a small fraction ofthe cross-sectional area of the line, means for injecting steam into theline at suicient distance from said reduced outlet and Without thevacuum chamber, whereby a pressure differential is built up' between theline side of the reduced outlet and the vacuum chamber side sufcient tocause violent and spontaneous expansion of the mixture introduced to thechamber, said outlet positioned centrally of the chamber and havingmounted thereon in surrounding relation, a downwardly inclined baiiie todischarge the mixture downwardly and outwardly in said chamber `,and infreely suspended finely broken state, the

outlet being suiliciently below the said pressure reducing passage toprevent entrainment and far enough from the bottom of the chamber togive the falling particles projected from the outlet a sucient time foradequate separation out of the vapor and liquid phase constituents, saidmeans for creating a reduced .pressure operating to remove vapor phaseconstituents through said passage, and another outlet remotely spacedfrom said passage for -removing liquid phase constituents.

2. An apparatus for treating liquids such as lactic uids comprising avacuum chamber, means for maintaining reduced pressure therein includinga Withdrawal passage adjacent one end of the chamber, a linecommunicating with a source of liquid supply and `extending within saidchamber, said line terminating at its end within the chamber in areduced outlet whose total cross-sectional area is a small fraction ofthe cross-sectional area of the line, means for injecting steam into theline at sumcient distance from said reduced outlet whereby a pressuredin'erential is built up between the line side of the reduced outlet andthe vacuum chamber side sumcient to cause violent and spontaneousexpansion of the mixture introduced to the chamber, said outlet havingmounted thereon in surrounding relation, a downwardly inclined batile todischarge the mixture downwardly and outwardly in said chamber and infreely suspended iinely broken state, the outlet being suillciently

